(i) Technical Field
The present invention relates to a booklet loading apparatus on which plural booklets are loaded, a post-treatment apparatus, and an image forming system.
(ii) Description of the Related Art
Conventionally there is well known a booklet loading apparatus which is included in an image forming system typified by a printer or a copying. The loading apparatus is connected to the printer, and the loading apparatus accommodates folding sheets printed and bound while the folding sheets are loaded on the loading apparatus. The loading apparatus includes a belt conveyer which conveys the folding sheets after cutting. In the loading apparatus, an increase in loading capacity is achieved by accommodating the sheets in the belt conveyer.
FIG. 9 is a view showing a state in which the booklet is loaded by a conventional booklet loading apparatus. Part (a) to Part (d) of FIG. 9 show the state in which the booklet is loaded as time advances. Part (a) to Part (c) of FIG. 9 are both a plan view showing a part of the loading apparatus and a plan view of the loading apparatus.
A conventional loading apparatus 500 includes a carry-out roller 511, a transfer belt 512, and a loading tray 513. The carry-out roller 511 sequentially carries out the booklets. The transfer belt 512 transfers the booklet. The loading tray 513 raises the booklet, and the booklet is loaded on the loading tray 513. In Part (a) of FIG. 9, a first booklet P501 is already carried out from a carry-out roller 511 and loaded on a transfer belt 512, and a second booklet P502 is being carried out from a carry-out roller 511. The transfer belt 512 is moved by a predetermined distance in synchronization with timing at which the booklet is carried out from the carry-out roller 511. Therefore, the carried-out booklets are arranged on the carry-out roller 511 while overlapping one another.
The booklet carried out from the carry-out roller 511 is bound by folding the plural sheets into two half-divisions, and the booklet usually has a bulge near a back. The thickness of the booklet by the bulge frequently has deviation in a direction along the back. Therefore, in the loading apparatus 500, when the booklet P502 is loaded while overlapping the booklet P501, the booklet P502 is loaded while inclined as shown in Part (b) of FIG. 9. Then, a booklet P503 carried out in Part (c) of FIG. 9 is loaded while inclined by the same principle as the second booklet P502. As shown in Part (d) of FIG. 9, because an orientation of the each loaded booklet is shifted from one another, disturbing the alignment of the booklet, the booklet to easily drops out. When the carry-out of the booklet is continued to load the booklet while the booklet is raised by the loading tray 513, a situation which the booklet falls or drops out is further easily generated. Accordingly, an amount of loadable booklet is remarkably restricted. Appearance of the loading state is degraded when viewed from a user.